A vane pump is known as one of gas pumps such as a vacuum pump and a compressor, which are arranged to suck and deliver a gas. The vane pump includes a housing, a rotor and at least one vane, which cooperate to define a plurality of variable-volume chambers. The volume of each variable-volume chamber is increased and decreased during rotation of the rotor, to thereby suck and deliver the gas. The gas vane pump may be of an intermittent lubrication type wherein a lubricant for lubricating sliding portions of the housing, rotor and vane(s) is intermittently introduced into the housing as the rotor is rotated. JP-3-115792A discloses a gas vane pump equipped with a metering device arranged to introduce a metered amount of lubricant into the housing per each revolution of the rotor, for preventing an excessively large amount of supply of the lubricant into the housing. This metering device also functions to prevent an unnecessary supply of the lubricant into the housing after termination of the rotary motion of the rotor.